198189405 has 24 divisors (see below), whose sum is σ = 344885112. Its totient is φ = 105283584.

The previous prime is 198189403. The next prime is 198189443. The reversal of 198189405 is 504981891.

It can be written as a sum of positive squares in 4 ways, for example, as 16990884 + 181198521 = 4122^2 + 13461^2 .

It is not a de Polignac number, because 198189405 - 2¹ = 198189403 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198189401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2997 + ... + 20133.

It is an arithmetic number, because the mean of its divisors is an integer number (14370213).

Almost surely, 2^198189405 is an apocalyptic number.

198189405 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

198189405 is a deficient number, since it is larger than the sum of its proper divisors (146695707).

198189405 is a wasteful number, since it uses less digits than its factorization.

198189405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17405 (or 17402 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 45.

The square root of 198189405 is about 14077.9758843379. The cubic root of 198189405 is about 583.0334580231.

The spelling of 198189405 in words is "one hundred ninety-eight million, one hundred eighty-nine thousand, four hundred five".